Replaceable mower blade and assembly

ABSTRACT

A replaceable mower blade for attachment to a mounting member operatively connected to a mower is provided. The blade includes a central portion having opposing side edges, a top surface, and a bottom surface. The blade also includes a tip portion extending from the central portion. The central portion includes at least one attachment mechanism for operatively connecting the blade to the mounting member.

FIELD OF THE INVENTION

The present invention relates to lawn and garden equipment, and moreparticularly, to a replaceable blade assembly for a mower.

BACKGROUND OF THE INVENTION

Lawn mowers such as walk-behind mowers, riding mowers, garden tractors,and the like include a cutting deck that includes at least one cuttingblade configured to cut grass and other vegetation. However, the cuttingblade often contacts rocks, tree branches, or other debris which causesthe blade to dull or otherwise become ineffective. Typical changeableblades for rotary mowers include one-piece blades that are attached andretained using hardware which requires tools to remove and replace theblade, pivot-blades attached onto one-piece mounting plates which alsorequire tools to remove and replace the blade, and one-piece blades thatare attached and retained but do not require tools for removal andreplacement. Replacement of the one-piece blades involves replacing theentire blade even though one of the sharpened edges may not needreplacement. Also, the one-piece blades are also typically designed forfinish-cut operations, and where durability and impact strength aremajor concerns, damage to spindles, motors and engine crankshafts withone piece blades might not be avoidable. Pivot-blades are often used inrough-cut operations and typically do not produce high cutting quality.

For high quality cutting operations, the cutting blades need to bestable and solidly retained to provide the highest quality of cut andsafe operation.

Therefore, a need exists for a mower blade assembly having replaceableblades that can be easily replaced without the need for tools. A needalso therefore exists for a mower blade assembly in which the blades arereplaceable and self-securing while also being easily removable.

BRIEF SUMMARY OF THE INVENTION

According to one aspect of the present invention, a replaceable bladefor attachment to a mounting member of a lawn mower is provided. Thereplaceable blade includes a central portion having an upper surface, alower surface, opposing side edges, and an end extending between theside edges. The replaceable blade also includes a tip portion extendingfrom the central portion opposite the end. The replaceable blade furtherincludes at least one attachment mechanism included on the centralportion.

According to another aspect of the present invention, a replaceableblade for attachment to a mounting member of a lawn mower is provided.The replaceable blade includes a central portion having an uppersurface, a lower surface, opposing side edges, and an end extendingbetween the side edges. The replaceable blade also includes a tipportion extending from the central portion. A plurality of apertures areformed through the central portion.

According to yet another aspect of the present invention, a replaceableblade for attachment to a mounting member of a lawn mower is provided.The replaceable blade includes a central portion having an uppersurface, a lower surface, and a thickness extending between the uppersurface and the lower surface. The replaceable blade includes a tipportion extending from the central portion. A first attachment mechanismis positioned on the central portion, and a second attachment mechanismis positioned on the central portion. The first and second attachmentmechanisms selectively connect the central portion to the mountingmember.

Advantages of the present invention will become more apparent to thoseskilled in the art from the following description of the embodiments ofthe invention which have been shown and described by way ofillustration. As will be realized, the invention is capable of other anddifferent embodiments, and its details are capable of modification invarious respects.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

These and other features of the present invention, and their advantages,are illustrated specifically in embodiments of the invention now to bedescribed, by way of example, with reference to the accompanyingdiagrammatic drawings, in which:

FIG. 1 is a top perspective view of an embodiment of a replacement mowerblade assembly;

FIG. 2 is a bottom perspective view of the blade assembly shown in FIG.1;

FIG. 3 is an exploded view of the blade assembly shown in FIG. 1;

FIG. 4 is top and bottom perspective views of an exemplary embodiment ofa mounting member;

FIG. 5 is top and bottom perspective views of an exemplary embodiment ofa locking mechanism;

FIG. 6 is top and bottom perspective views of an exemplary embodiment ofa cutting blade;

FIG. 7 is a top view of another exemplary embodiment of a mountingmember; and

FIG. 8 is a top view of another exemplary embodiment of a lockingmechanism.

It should be noted that all the drawings are diagrammatic and not drawnto scale. Relative dimensions and proportions of parts of these figureshave been shown exaggerated or reduced in size for the sake of clarityand convenience in the drawings. The same reference numbers aregenerally used to refer to corresponding or similar features in thedifferent embodiments. Accordingly, the drawing(s) and description areto be regarded as illustrative in nature and not as restrictive.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1-2, an exemplary embodiment of a replacement mowerblade assembly 10 is shown. The blade assembly 10 includes a mountingmember 12, a pair of opposing replaceable blades 16, and a plurality ofattachment mechanisms for releasably attaching each of the replaceableblades 16 to the mounting member 12. The attachment mechanisms areconfigured to allow each blade 16 to be attachable to any end of themounting member 12 while also preventing the blade 16 from beingattached to the mounting member 12 in an upside-down manner. Improperattachment of the blade(s) 16 to the mounting member 12 causes arotational imbalance of the blade assembly 10 which, in turn, causesimmediate wear-and-tear on the engine and rotational components thereofdue to the shaking and vibrations caused by the rotational imbalance ofthe blade assembly 10. The mounting member 12 is operatively positionedwithin a cutting deck of any type of lawn mower, including a walk-behindstyle lawn mower, a garden tractor, a riding lawn mower, or the like. Inan embodiment, the blade assembly 10 is connected to a motor or enginecrankshaft (not shown) that extends downwardly through the cutting deck.In another embodiment, the blade assembly 10 is connected to a rotatablespindle (not shown) located within a cutting deck. The blade assembly 10is removably connected within the deck and is rotatable about asubstantially vertical rotational axis defined by the motor or enginecrankshaft or the spindle to which it is attached.

In the exemplary embodiment illustrated in FIGS. 1-4, the mountingmember 12 is an elongated structural member that provides a base forreceiving at least one removably attachable replacement blade 16. Themounting member 12 includes a first end 18, a second end 20 opposite thefirst end 18, an upper surface 22, an opposing lower surface 24, a firstside edge 26 extending between the opposing ends 18, 20, and an opposingsecond side edge 28. The upper and lower surfaces 22, 24 form asubstantially planar central portion of the mounting member 12. In theillustrated exemplary embodiment, the opposing side edges 26, 28 extendfrom the central portion in a curved manner. In an embodiment, the sideedges 26, 28 are curved upwardly relative to the upper surface 22 of themounting member 12. In the illustrated exemplary embodiment, the sideedges 26, 28 are curved in a corresponding direction such that themounting member 12 has a C-shaped or channel-shaped cross-section. TheC-shaped cross-sectional shape increases the beam strength of themounting member 12. It should be understood by one of ordinary skill inthe art that the mounting member 12 may also have any other similarcross-sectional shape that increases the beam strength. The curved sideedges 26, 28 provide additional structural stiffness or rigidity to themounting member 12 to resist longitudinal bending and torsional rotationwhile minimizing losses in efficiency due to contact with the cutgrasses. In an embodiment, the side edges 26, 28 are curved relative tothe upper surface 22 at an angle of between about 30° to 90°. In anotherembodiment, the opposing side edges 26, 28 of the mounting member 12 arecurved downwardly toward the lower surface 24 of the mounting member 12.In yet another embodiment, the central portion of the mounting member 12is substantially planar between the opposing side edges 26, 28 such thatthe opposing side edges 26, 28 are not curved and remain substantiallycoplanar with the upper and lower surfaces 22, 24.

In an embodiment, the mounting member 12 includes a central bore 30formed through the thickness thereof, as shown in FIGS. 1-4. The centralbore 30 is sized and shaped to receive a rotatable driving member suchas a motor or engine crankshaft, a spindle, an adaptor, or any otherrotatable member configured to be positioned within the central bore tocause the blade assembly 10 to selectively rotate about an axissubstantially perpendicular to the upper surface 22. In an embodiment,the central bore 30 has a generally elongated X-shape, as shown in FIG.4. In another embodiment, the central bore 30 has a six-point starshape, as shown in FIG. 7. It should be understood by one of ordinaryskill in the art that the central bore 30 can be formed of any shapesufficient to receive a rotatable member that causes the blade assembly10 to rotate thereabout.

In the exemplary embodiment illustrated in FIGS. 1-4 and 6, the mountingmember 12 includes a first attachment mechanism 210 formed of aplurality of caps 32 extending from the mounting member 12 for providinga releasable attachment between the replacement blades 16 and themounting member 12. The first attachment mechanism 210 is positionedadjacent to both the first end 18 and the opposing second end 20thereof. The first attachment mechanism 210 provides a male portion of amale-female connection. In another embodiment, the first attachmentmechanism 210 operatively connected to the mounting member 12 mayinclude the female portion of a male-female connection. Each firstattachment mechanism 210 on the mounting member 12 is configured tocooperate with a corresponding attachment mechanism operativelyconnected to each blade 16. It should be understood by one of ordinaryskill in the art that the first attachment mechanism 210 can be formedof any mechanical connection that allows for a tool-less quick-releaseand quick-attachment of a blade 16 to a distal end 18, 20 of themounting member 12.

In an embodiment, the first attachment mechanism 210 is located adjacentto both the first end 18 and the second end 20 of the mounting member12, wherein each first attachment mechanism 210 includes at least onecap 32 that extends perpendicularly away from the lower surface 24 ofthe mounting member 12. The illustrated exemplary embodiment of thefirst attachment mechanism 210 includes three caps 32 extending from thelower surface 24 of the mounting member 12, as shown in FIG. 4. Itshould be understood by one of ordinary skill in the art that althoughthe illustrated embodiment includes three (3) caps 32, the firstattachment mechanism 210 can include any number of caps extending fromthe lower surface 24 of the mounting member 12. The caps 32 protrudefrom the mounting member 12, and each cap 32 includes a base 34 thatextends substantially linearly away from the lower surface 24 and aflange 36 that extends substantially perpendicular and radially from thebase 34. The flange 36 is spaced apart relative to the lower surface 24,thereby providing a shoulder bolt having a gap between the base 34 andthe outer radial edge of the flange 36 to create a shoulder between theflange 36 and the lower surface 24 of the mounting member 12.

In an embodiment, the base 34 is a cylindrical member having a circularcross-sectional shape extending from the lower surface 24 of themounting member 12. In another embodiment, the cross-sectional shape ofthe base 34 can be oval, triangular, square, or the base 34 may includea plurality of vertically-oriented splines, a keying protrusion, half ofa yin/yang, or any symmetrical or non-symmetrical shape. In anembodiment, the flange 36 is a round, substantially flat plate mountedatop the end of the base 34. In another embodiment, the planar shape ofthe flange 36 can also be square, tear-dropped, half of a yin/yang,M-shaped, oval, square, triangular, or any symmetrical ornon-symmetrical shape. It should be understood by one of ordinary skillin the art that the base 34 and flange 36 can be any shape sufficient toallow the blades 16 to be releasably attachable to the mounting member12 by way of the caps 32. It should also be understood by one ofordinary skill in the art that the caps 32 can be formed of separateparts such as the bases 34 and flanges 36 formed separately and thenfixedly attached to each other or they could be integrally formedtogether in which the bases 34 and the flanges 36 are formed as a singlemember. In an embodiment, the base 34 and flange 36 of each cap 32 hasthe same size and shape. In another embodiment, at least one cap 32 issized differently than the other caps 32. For example, one cap 32 mayinclude a larger base 34, a larger flange 36, or a combination of bothrelative to the other caps 32. Alternatively, one cap 32 may have asquare base 34, a square flange 36, or a combination of both while allother caps 32 have a circular base and circular flange 36. In stillanother alternative example, one cap 32 may have a circular base 34 anda square flange 36 while all other caps 32 have a circular base andcircular flange 36. Providing a first attachment mechanism 210 with onecap 32 different than the others can assist in ensuring that the blade16 cannot be attached to the mounting member 12 in an upside-downmanner.

In the exemplary embodiment illustrated in FIG. 4, all of the caps 32 ofthe first attachment mechanism 210 positioned adjacent to each opposingdistal end 18, 20 extend from the lower surface 24 of the mountingmember 12. In another embodiment, all of the caps 32 for the firstattachment mechanism 210 for connecting the blades 16 to a respectiveend of the mounting member 12 extend from a surface of the blade 16 andthe caps 32 are received by the mounting member 12. In yet anotherembodiment, at least one of the caps 32 from a first attachmentmechanism 210 extends from the lower surface 24 of the mounting member12 and at least another cap 32 extends from the corresponding blade 16,wherein each of the caps 32 is configured to assist in attaching theblade 16 to the mounting member 12.

The function of the caps 32 of the first attachment mechanism 210 is toallow the replacement blades 16 to be selectively and releasablyconnectable to the mounting member 12, as will be explained below. Inthe illustrated exemplary embodiment, the caps 32 of each of the firstattachment mechanism 210 positioned adjacent to the first and secondends 18, 20 of the mounting member form two opposing patterns of caps32, wherein each pattern includes three (3) caps 32. Each firstattachment mechanism 210 should include at least one cap 32, wherein thecap(s) form a pattern. It should be understood by one of ordinary skillin the art that the first attachment mechanism 210 may include anynumber of caps 32 for operatively connecting a replacement blade 16 tothe mounting member 12, but a pattern having at least three caps 32 ispreferable to more evenly distribute the stresses transferred to themounting member 12 by the replacement blades 16 while utilizing thefewest number of caps 32. In the illustrated embodiment, each firstattachment mechanism 210 includes a pattern of three caps 32, and thepattern of caps 32 can be arranged such that the linear alignmentbetween any two of the caps 32 is not parallel to the longitudinal ortransverse axes of the replacement blade 16 or the mounting member 12 towhich they are attached. In another embodiment, at least two of the caps32 of a first attachment mechanism 210 are aligned such that the linearalignment of the caps 32 is parallel or perpendicular to thelongitudinal axis of the mounting member 12. In an embodiment, thepattern of the caps 32 of each first attachment mechanism 210 isidentical such that a replacement blade 16 having a pattern ofconnecting mechanism that cooperates with the caps 32 can be attached toeither end of the mounting member 12. In another embodiment, the patternof the caps 32 of the opposing first attachment mechanisms 210 isdifferent such that the replacement blades 16 are configured to beattachable to only one of the ends of the mounting member 12 withoutbeing attachable to any other end of the mounting member. In anembodiment, the pattern of caps 32 forming the first attachmentmechanism 210 is asymmetrical about the longitudinal axis of the blade16, as shown in FIG. 4. In another embodiment, the pattern of caps 32forming the first attachment mechanism 210 is symmetrical about thelongitudinal axis of the blade 16.

The caps 32 can also be arranged in a pattern that ensures properreplacement blade orientation and alignment when installed, wherein thepattern allows the blade 16 to be attached such that the tip portion ofthe blade 16 is properly oriented during rotation. In an embodiment, thecaps 32 are welded to the mounting member 12 or blade 16. In anotherembodiment, the caps 32 are riveted to the mounting member 12 or blade.It should be understood by one of ordinary skill in the art that thecaps 32 can be attached to the mounting member 12 or the blade 16 in anymanner so as to provide a fixed rigid connection therebetween. Althoughthe first attachment mechanism 210 is described above as including aplurality of caps 32 for providing a male-female connection, it shouldbe understood by one of ordinary skill in the art that the firstattachment mechanism 210 can include any form of male or femaleconnector that is receivable by a corresponding female or male connectorof an attachment mechanism for connecting a blade 16 to the mountingmember 12.

In an embodiment, a second attachment mechanism 212 for releasablyconnecting the blades 16 to the mounting member 12 is formed as anindexing member 14, as shown in FIGS. 1, 3, and 5. The indexing member14 of the second attachment mechanism 212 cooperates with acorresponding attachment mechanism included on both the mounting member12 and each blade 16 for receiving the indexing member 14, as will beexplained below. The attachment mechanism on the mounting member 12configured to receive the indexing member 14 is a third attachmentmechanism 214 positioned adjacent to both the first and second distalends 18, 20 thereof. Each third attachment mechanism 214 included on themounting member 12 is formed of an indexing aperture 38 formed throughthe thickness of the mounting member 12, as shown in FIG. 4, therebyproviding the mounting member 12 with a plurality of third attachmentmechanisms 214. The indexing aperture 38 of each blade 16 is configuredto receive the indexing member 14 when the respective blade 16 isproperly aligned and attached to the mounting member 12. In theillustrated exemplary embodiment shown in FIG. 4, the indexing apertures38 have a substantially circular shape, but it should be understood byone of ordinary skill in the art that the indexing apertures 38 can beformed as any shape that corresponds to the pins 44 of the indexingmember 14.

As explained above and shown in FIGS. 1-3 and 5, the second attachmentmechanism 212 is formed as an indexing member 14. Cooperating andcorresponding indexing apertures 38, 60 are formed into the mountingmember 12 and replacement blades 16 for receiving the indexing member 14when each blade 16 is positively positioned with respect to the mountingmember 12. In an embodiment, the indexing member 14 is fixedly attachedto the mounting member 12. In another embodiment, the mounting member 12is positioned adjacent to the upper surface 22 of the mounting member 12and is secured in a sandwiching manner between the mounting member 12and the motor or engine crankshaft, the spindle, or an adaptor attachedto the crankshaft or spindle. The indexing member 14 is an elongatedmember having a rectangular base 40, a pair of arms 42 extending fromopposing ends of the base 40, and a pin 44 or tab extending from the endof each arm 42 opposite the base 40. It should be understood by one ofordinary skill in the art that the indexing member 14 may be formed ofany shape. The pins 44 are biased toward engagement with both themounting member 12 and the blades 16 due to the cantilever configurationof the pins 44 being positioned at the distal end of the arms 42 withthe base 40 being substantially stationary or otherwise operativelysecured to the mounting member 12. Each pin 44 is movable or actuatablefor selectively releasing or engaging a replacement blade 16 and themounting member 12, as will be explained below. In an embodiment, thearms 42 are aligned with the base 40, and each arm 42 has a width thatis smaller than the width of the base 40. Although the arms 42 areillustrated as having a smaller width than the base 40 in the exemplaryembodiment, it should be understood by one of ordinary skill in the artthat the base 40 can also include the arms 42 such that the pins 44extend from the base 40 which has a substantially consistent width alongthe length thereof. The arms 42 and the elongated base 40 are configuredto act as cantilever springs when the indexing member 14 is securedabout the central aperture 46. The pins 44 extend away from the plane ofthe base 40 and arms 42, wherein the pins 44 are configured to extendthrough the indexing aperture 38 (FIG. 4) of the mounting member 12.Each pin 44 is configured to be selectively engaged with a replacementblade 16.

FIG. 6 illustrates an exemplary embodiment of a replaceable replacementblade 16 that is configured to be selectively attachable to either thefirst end 18 or the second end 20 of the mounting member 12. Thereplacement blade 16 includes a central portion 48 and a tip portion 50integrally formed with and extending from the central portion 48. Thecentral portion 48 is configured to be operatively connected to themounting member 12 while the tip portion 50 extends beyond thecorresponding distal end 18, 20 of the mounting member 12 for cuttinggrass and vegetation. The central portion 48 includes an upper surface52, a lower surface 54, opposing side edges 56, and at least oneattachment mechanism. In the illustrated exemplary embodiment, thecentral portion 48 of the blade includes a fourth attachment mechanism216 and a fifth attachment mechanism 218. The upper and lower surfaces52, 54 form a substantially flat body, and the opposing sides edges 56extend from the body in a curved or formed angular sections. In anembodiment, the side edges 56 of the replacement blade 16 have a similarcurvature as the first and second side edges 26, 28 of the mountingmember 12 such that when the replacement blade 16 is attached to themounting member 12, the curved edges of both the mounting member 12 andthe blade 16 form a nesting arrangement. The matching channel shapes ofthe central portion 48 of the replacement blade 16 and the mountingmember 12 reduce the shear loading of the caps 32 during conditions suchas blade impact, whereby a majority of impact energy between thereplacement blade 16 and the object being impacted is diverted fromshear to tension. The central portion 48 includes a first end 58extending between the opposing side edges 56. In an embodiment, thefirst and second side edges 56, 58 are substantially aligned with theupper and lower surfaces 54, 56 in a co-planar manner, thereby forming aflat central portion 48. In the illustrated embodiment, the first end 58includes a notch 69 formed therein, wherein the notch 69 is configuredto provide clearance between the central portion 48 of the replacementblade 16 and an adapter (not shown) which is used to attach thereplacement blade 16 to an engine crankshaft.

As shown in FIG. 6, an exemplary embodiment of the central portion 48 ofthe replacement blade 16 includes the fourth attachment mechanism 216which is an indexing aperture 60 formed into the replacement blade 16for receiving the indexing member 14. The indexing aperture 60 of thereplacement blade 16 is configured to be alignable with the indexingaperture 38 of the mounting member 12 when the replacement blade 16 isproperly seated against and attached to the mounting member 12. Theindexing aperture 60 can be formed as any shape, but the shape of theindexing aperture 60 should be shaped to correspond to the shape of theindexing aperture 38 of the mounting member 12 and the shape of the pin44 of the indexing member 14.

The indexing aperture 60, forming the fourth attachment mechanism 216 inthe illustrated exemplary embodiment, is surrounded by the fifthattachment mechanism 218 which is formed as a plurality of lockingapertures 62, wherein each of the locking apertures 62 is configured toreceive a corresponding cap 32 extending from the mounting member 12 forselectively attaching the blade 16 to the mounting member 12. In theembodiment illustrated in FIG. 6, the locking apertures 62 are formed askeyhole apertures which include a receiving portion 64 and a channelportion 66. The receiving portion 64 is a rounded hole formed throughthe thickness of the central portion 48 of the replacement blade 16. Thereceiving portion 64 is sized to allow the flange 36 of the cap 32 topass through. The channel portion 66 is an elongated channel extendingfrom the receiving portion 64. The channel portion 66 is sized to besubstantially the same (or slightly larger) than the outer diameter ofthe base 34 of the cap 32 such that the base 34 is capable of slidingalong the channel portion 66. The end of the channel portion 66 oppositethe receiving portion 64 is configured to be a stop to prevent thereplacement blade 16 from sliding past the end of the mounting member12. It should be understood by one of ordinary skill in the art thatalthough the locking apertures 62 are described above as keyholeapertures, the locking apertures 62 can also be formed as any shapesufficient to receive the corresponding caps 32 of the mounting memberfor positively securing each replacement blade 16 an end of the mountingmember 12. Also, the fifth attachment mechanism 218 is described aslocking apertures 62, or a female portion of a male-female connection,but it should be understood by one of ordinary skill in the art that thefifth attachment mechanism 218 may also be the male portion of amale-female connection or any other portion of a mechanical connectionthat allows the replacement blades 16 to be easily attachable andremovable from the mounting member 12 without the use of tools.

The tip portion 50 of the replacement blade 16 extends from the centralportion 48 opposite the first end 58, as shown in FIGS. 1-3 and 6. Thetip portion 50 of the replacement blade 16 can be shaped and configuredfor different operational purposes, such as grass cutting, materialcollection, mulching, “rough cut”, blowing, or the like. For example,for grass cutting operations, the tip portion 50 of the replacementblade 16 includes a sharpened edge configured to cut grass. High-qualitygrass cutting operations, such as “finish cutting” the replacementblades 16 need to be stable and solidly retained to provide the highestquality of cut and safe operation. “Rough cut” grass cutting operationsmay have a sharpened edge for cutting grass and other vegetation, butthe replacement blade 16 may include a pivot portion that pivots duringthe cutting operation which produces a reduced quality of cut relativeto a finish cut blade. The “rough cut” blade may also include a filamentattachment means. For grass cutting operations, the edge of thereplacement blade 16 opposite the sharpened cutting edge may form a sailor raised portion that produces increased air pressure above thereplacement blade 16 and reduced air pressure below so as to create liftfor the grass and clippings. For a blower operation, the tip portion 50can be shaped like an impeller such that the air movement into and outof the cutting deck in enhanced. This blower operation can be useful inclearing walkways, driveways, or the like. In other embodiments, the tipportion 50 can be formed to perform any of these or other operations, orany combination thereof.

In the illustrated embodiment, the tip portion 50 of the replacementblade 16 is configured as a mulching blade for not only cutting grassand vegetation but also to circulate the cut grass and vegetation foradditional contact and cutting to reduce the size of the particles forease of assimilation into the grass. As shown in FIG. 6, the tip portion50 extends from the central portion 48 and includes a leading edge 68, atrailing edge 70, and a distal end 72 extending between the leading andtrailing edges 68, 70 and located at the end of the tip portion 50opposite the central portion 48. The leading edge 68 is sharpened forcutting grass and other vegetation. In an embodiment, the leading edge68 is substantially linear between the central portion 48 and the distalend 72. In the illustrated embodiment, the leading edge 68 extendsbetween the central portion 48 and the distal end 72 in a nonlinearmanner, wherein the leading edge 68 includes a transition such that theportion of the leading edge 68 adjacent to the central portion 48 issubstantially coplanar therewith and the portion of the leading edge 68adjacent to the distal end 72 is vertically lower than the centralportion 48. In an embodiment, the leading edge 68 is sharpened theentire distance between the central portion 48 and the distal end 72 ofthe replacement blade 16. In another embodiment, the leading edge 68 ofthe replacement blade 16 is sharpened only a portion of the distancebetween the central portion 48 and the distal end 72. In an embodiment,the trailing edge 70 extending between the central portion 48 and thedistal end 72 is substantially linear. In the illustrated embodiment,the portion of the trailing edge 70 adjacent to the distal end 72 iscurved or formed angularly upwardly, thereby forming a sail or the like.This sail is configured to create lift, or a pressure differentialbetween the area above the tip portion 50 and below the tip portion 50.The lift generated by the sail causes the cut grass and vegetation to belifted and recirculated such that the sharpened leading edge 68 can cutthe vegetation multiple times and reduce the particle size thereof. Inanother embodiment, the sail can be designed primarily to lift and ejectthe cut grass for discharge and collection purposes.

In an embodiment, the replacement blades 16 are formed of the samematerial as the mounting member 12 to which they are attached. Inanother embodiment, the replacement blades 16 are formed of a differentmaterial than the mounting member 12, wherein the material used for thereplacement blades 16 can be chosen to optimize wear resistanceproperties as well as provide a high hardness for durability. In yetanother embodiment, the mounting member 12 may be formed of a differentmaterial than the replacement blades 16, wherein the material used forthe mounting member 12 can be chosen to optimize the energy absorptionproperties of the mounting member 12 to increase durability and reducethe stresses and wear-and-tear on the replacement blades 16.

Initial assembly of the blade assembly 10 includes positioning theindexing member 14 immediately adjacent to the upper surface 22 of themounting member 12 such that the central aperture 46 of the indexingmember 14 and the central bore 30 of the mounting member 12 aresubstantially aligned. Then, each pin 44 of the indexing member 14extends through a corresponding indexing aperture 38 in the mountingmember 12. Once the pins 44 extend through the indexing apertures 38 andthe central bore 30 receives the rotary drive mechanism, the mountingmember 12 is positively secured to the rotatable engine or motorcrankshaft or spindle (not shown) such that the curved first and secondside edges 26, 28 are directed upwardly away from the ground. Securingthe mounting member 12 to the motor or engine crankshaft or spindle alsosecures the indexing member 14 therebetween, thereby preventing movementor rotation of the indexing member 14 relative to the mounting member12. A replacement blade 16 is then attached to mounting member 12 byaligning the receiving portion 64 of the locking apertures 62 of thereplacement blade 16 with the flanges 36 of the caps 32 of the mountingmember 12. The replacement blade 16 is then pushed against the mountingmember 12 and pulled radially outward until the bases 34 of the caps 32contact the ends of the channel portions 66 of the locking apertures 62.Once the caps 32 contact the ends of the locking apertures 62, the pins44 of the indexing member 14 are biased by the spring configuration ofthe indexing member 14 into engagement with the indexing apertures 60 ofthe replacement blade 16 such that the pins 44 extend through both themounting member 12 as well as the indexing apertures 60 of thereplacement blade 16. The same method is used to attach a secondreplacement blade 16 to the opposing end of the mounting member 12.

In operation, as the blade assembly 10 rotates about the spindle, motor,or engine crankshaft to which it is attached, the centrifugal force onthe replacement blades 16 ensures a positive attachment between thereplacement blades 16 and the mounting member 12 by forcing the caps 32of the mounting member into contact with the end of each receivingportion 64 of the locking aperture 62 of the replacement blade 16. Thereplacement blades 16 and the blade assembly 10 can be configured forclockwise or counterclockwise rotation about the spindle, motor, orengine crankshaft.

For toolless removal and replacement of one or both of the replacementblades 16 from the mounting member 12, the pin 44 positioned within theindexing aperture 60 of the replacement blade 16 being removed ispressed such that the pin 44 disengages from the replacement blade 16.Once the pin 44 has been pushed out of the indexing apertures 60 of thereplacement blade 16, the replacement blade 16 is pushed toward thecentral bore 30 of the mounting member 12 in a sliding motion such thatthe bases 34 of the caps 32 slide into the receiving portions 64 of thelocking apertures 62. The replacement blade 16 is then pulled downwardlyaway from the mounting member 12 as the flanges 36 pass through thereceiving portions 64, thereby completely disengaging the replacementblade 16 from the mounting member 12. Replacement of the replacementblade 16 includes repeating the step described above for attaching thereplacement blade 16 to the mounting member 12.

In another embodiment of the blade assembly 10, the replacement blade 16includes the caps 32 extending therefrom while the mounting memberincludes the corresponding keyhole apertures.

Another exemplary embodiment of the mounting member 112 of the bladeassembly 10 is shown in FIG. 7. The mounting member 112 includes acentral bore 30 formed through the thickness thereof. The mountingmember 112 further includes a first end 118, a second end 120, and athird end 121 extending radially outward relative to the central bore30. In an embodiment, each of the ends 118, 120, 121 extend radiallyoutward and oriented at about 120° relative to each other such that theyare equally spaced from each other. In another embodiment, the angularorientation can be unequally spaced for noise abatement or otherpurposes. The three-end mounting member 112 allows for a replacementblade 16 to be attached to each of the ends 118, 120, 121, therebyproviding a blade assembly 10 having three replacement blades 16. Itshould be understood by one of ordinary skill in the art that thepattern of caps 32 extending from the mounting member adjacent to eachend should be the same for each end such that a single replacement blade16 design can be used for all different variations of the mountingmember.

As shown in FIG. 8, another exemplary embodiment of the indexing member114 is shown. The indexing member 114 includes a base 140 and three arms142 extending from the base 140. The arms 142 are oriented at about 120°relative to each other. A pin 144 is located at the end of each arm 142opposite the base 140. The indexing member 114 is configured to bepositioned immediately adjacent to the mounting member 112 such thateach of the pins 144 engages a corresponding indexing aperture of themounting member 112. It should be understood by one of ordinary skill inthe art that although the illustrated embodiments of the mounting member12, 112 and indexing member 14, 114 have a 2- or 3-end shape, any numberof a plurality of ends and arms can extend from the central bore 30provided that the blade assembly 10 remains balanced about the centralbore 30 as it rotates.

In an embodiment, the mounting member 12, the indexing member 14, andthe replacement blades 16 are all formed of the same material. Inanother embodiment, the replacement blade 16 can be formed of adifferent material than the mounting member 12, thereby providingdesirable properties to the replacement blade 16 which can increase thequality of cut of the sharpened edge while the material of the mountingmember 12 can provide the strength and rigidity to allow for longer lifeof the replacement blades 16.

The blade assembly 10, as shown and described above, allows forreplacement blades 16 to be easily attached or detached without the useof tools. Instead, the pins are actuatable, or pushable, which allows areplacement blade to be detachable from the mounting member. The pinsalso ensure proper engagement between the cutting blades and themounting member by way of an indexing or positive locating attachmentdue to the biasing of the pins into engagement with the indexingapertures formed through both the mounting member and the blades.

In each of the exemplary embodiments of the blade assembly 10, thereplaceable replacement blades 16 are attachable to an end of themounting member 12. The blade assembly 10 includes at least oneattachment mechanism configured to cooperate with correspondingattachment mechanism(s) to positively position and retain eachreplacement blade 16 to the mounting member 12 until an operatorselectively removes or otherwise disengages one or more of thereplacement blades 16 from the mounting member 12. For example, in theembodiment in which the first attachment mechanism 210 is a plurality ofcaps 32 extending from either the mounting member 12 or a blade 16, andthe first attachment mechanism 210 corresponds with the fifth attachmentmechanism 218 that includes a plurality of locking apertures 62 formedinto the other of the mounting member 12 or replacement blade 16. Thisconnecting mechanism allows each of the replacement blades 16 to besecured to the mounting member 12. Another connecting mechanism includesthe second attachment mechanism 212 which is formed as the indexingmember 14 that has a pin 44 positioned at a distal end of each arm 42,wherein each pin 44 is received within a corresponding third attachmentmechanism 214 formed as an indexing aperture 38 through the mountingmember and a corresponding fourth attachment mechanism 216 formed as anindexing aperture 60 through each replacement blade 16. As such, whenthe replacement blade(s) 16 is properly aligned with an end of themounting member 12, the pin 44 is biased into both indexing apertures38, 60 to positively locate the replacement blade 16 relative to thecorresponding end of the mounting member 12. It should be understood byone of ordinary skill in the art that other attachment mechanisms can beused to positively secure and position the replacement blades 16relative to the mounting member 12.

While preferred embodiments of the present invention have beendescribed, it should be understood that the present invention is not solimited and modifications may be made without departing from the presentinvention. The scope of the present invention is defined by the appendedclaims, and all devices, processes, and methods that come within themeaning of the claims, either literally or by equivalence, are intendedto be embraced therein.

What is claimed is:
 1. A replaceable blade for attachment to a mountingmember of a lawn mower, said blade comprising: a central portion havingan upper surface, a lower surface, opposing side edges, and an endextending between said side edges; a tip portion extending from saidcentral portion opposite said end; and at least one attachmentmechanism, wherein each of said at least one attachment mechanism islocated on said central portion.
 2. The replaceable blade of claim 1,wherein one of said at least one attachment mechanism is a plurality oflocking apertures formed through said central portion.
 3. Thereplaceable blade of claim 2, wherein each of said plurality of lockingapertures is formed as keyhole aperture.
 4. The replaceable blade ofclaim 2, wherein said plurality of locking apertures includes threelocking apertures forming a pattern, and wherein a line extendingbetween of any two of said three locking apertures is not parallel to alongitudinal axis or a lateral axis of said central portion.
 5. Thereplaceable blade of claim 2, wherein another of said at least oneattachment mechanism is an indexing aperture formed through said centralportion, and wherein said indexing aperture is surrounded by saidplurality of locking apertures.
 6. The replaceable blade of claim 1,wherein one of said at least one attachment mechanism is an indexingaperture formed through said central portion.
 7. The replaceable bladeof claim 1, wherein one of said at least one attachment mechanism is aplurality of caps extending from said upper surface of said centralportion.
 8. The replacement blade of claim 1, wherein said opposing sideedges are curved.
 9. The replacement blade of claim 8, wherein saidopposing side edges are curved upwardly relative to said upper surface.10. A replaceable blade for attachment to a mounting member of a lawnmower, said blade comprising: a central portion having an upper surface,a lower surface, and opposing side edges; a tip portion extending fromsaid central portion; and a plurality of apertures formed through saidcentral portion.
 11. The replaceable blade of claim 10, wherein at leasttwo of said plurality of apertures formed through said central portionare formed as keyhole apertures.
 12. The replaceable blade of claim 10,wherein one of said plurality of apertures is an indexing aperture. 13.The replaceable blade of claim 10, wherein said plurality of aperturescomprise a first attachment mechanism and a second attachment mechanism.14. The replaceable blade of claim 13, wherein said first attachmentmechanism includes one of said plurality of apertures formed as anindexing aperture.
 15. The replaceable blade of claim 13, wherein saidsecond attachment mechanism includes at least two of said plurality ofapertures formed as locking apertures.
 16. The replaceable blade ofclaim 15, wherein said locking apertures are formed as keyholeapertures.
 17. A replaceable blade for attachment to a mounting memberof a lawn mower, said blade comprising: a central portion having anupper surface, a lower surface, and a thickness extending between saidupper surface and said lower surface; a tip portion extending from saidcentral portion; a first attachment mechanism positioned on said centralportion; and a second attachment mechanism positioned on said centralportion, wherein said first and second attachment mechanisms selectivelyconnect said central portion to said mounting member.
 18. Thereplaceable blade of claim 17, wherein said first attachment mechanismincludes a portion of a male-female connection.
 19. The replaceableblade of claim 17, wherein said first attachment mechanism is formed atleast one locking aperture formed through said thickness of said centralportion.
 20. The replaceable blade of claim 19, wherein said at leastone locking aperture is a plurality of locking apertures, and each ofsaid plurality of locking apertures is formed as a keyhole aperture. 21.The replacement blade of claim 19, wherein said at least one lockingaperture is a plurality of locking apertures forming a pattern on saidcentral portion, and wherein alignment of any two of said plurality oflocking apertures is non-parallel relative to a longitudinal axis and alateral axis of said central portion.
 22. The replaceable blade of claim17, wherein said second attachment mechanism is formed as an indexingaperture formed through said thickness of said central portion.